This invention relates generally to golf clubs and, in particular, to so-called metal wood drivers.
Recent developments in golf club design have included improvements in drivers, which are clubs used primarily to strike a golf ball resting on a golf tee. These improvements have resulted in drivers with club heads consisting of a hollow shell usually made of metal, such as steel, aluminum, or titanium. These hollow shells typically have a weight pad located on the sole of the club for the purpose of moving the center of gravity downward toward the sole and inward toward the heel of the club head. One example of a golf club head consisting of a hollow metal shell with a weight pad is disclosed in U.S. Pat. No. 5,851,160 to Rugge, et al. According to Rugge, et al., moving the center of gravity to a position below the center of the impact face reduces the amount of backspin imparted to the golf ball by creating a counteracting torque couple between the impact point and the center of gravity of the club.
In an effort to obtain better and better performance from these hollow metal wood drivers, golf club manufacturers have increased the head volume from a moderate volume of 250 cc's as disclosed in Rugge, et al. to over 400 cc's in recent years. As head size increases, less and less material is available for inefficient structures such as weight pads while maintaining the club head of these super-oversized drivers within acceptable weight limitations (i.e., around 200 grams mass). Moreover, as the club head volume increases, the moment of inertia of the club heads also increase, leading to poor performance if prior art methods of locating the center of gravity below the center of the club face are followed.